Acid monoazo dyestuffs



United States Patent 3,104,237 ACiD MONDAZO DYESTUFFS Franz Frisch, Ariesheim, near Basel, Switzerland, assignor to Sandoz Ltd., Basel, Switzerland 7 No Drawing. Filed July 13, 1959, Ser. No. 826,445 Claims priority, application Switzerland Aug. 14, 1958 3 Claims. (Cl. 260-196) The present invention relates to acid monoazo dyestuffs of the formula wherein x represents the simple linkage or an oxygen atom,

R and R represent radicals of the benzene series which may be further substituted,

R represents hydroxyl, and

R represents hydrogen or alkyl which may be substituted,

and wherein N:=N stands in ortho-position to R x--O S- and the whole molecule contains one sulfonic acid group.

, The process for their production consists in coupling in the 1 position 1 mole of the diazo compound of an amine of the formula wherein:

R and R represent radicals of the benzene series which may be substituted, and

x represents an oxygen atom,

and wherein NH stand-s in ortho position to R x-O S-, with 1 mole of a coupling component R represents hydroxyl, and R represents hydrogen or alkyl which may be substituted,

wherein the reactants being so chosen that the resulting monoazo dyestulf contains one sulfonic acid group.

Examples of substituents which may be contained in the radicals R and R are, e.g., halogen atoms (chlorine, bromine), low molecular alkyl or alkoxy groups (methyl, ethyl, isopropyl, methoxy, ethoxy), the sulfonic acid group, sulfonic acid aryl ester groups such as the sulfonic acid p-henyl, sulfonic acid-4-methyl-, 4-chloroor 4-methoxyphenyl esters, the sulfonic acid amide group which may be substituted, e.g. sulfonic acid methylto dodecylamide, dimethylto dihexylamide, Z-hydroxyethyl-, 2- or 3-hydroxypropyl-, 2-ethoxyethyl-, 3-methoxypropyl-, 3- or 4-methoxybutylamide, di-(2-hydroxyetl1yl)-, di-(2- or 3-hydroxypropyl)-amide, phenyl-, 2-, 3- or 4-methylphenyl-, chlorophenyl-, methoxyphenylor -ethoxyphenylamide, N-methyl-N-phenyl-, N-ethyl-N- phenyl-, N-Z-hydroxyethyl-N-phenyl-, N-methoxypropyl- N-phenylamide and sulfonic acid cyclohexyland dicyclohexylamide.

The butyl, amyl, octyl and cyclohexyl groups are especially interesting as substituents of R The substituent R is preferably a hydrogen atom, a

methyl, ethyl, propyl, 2-hydroxyethyl-, 2- or 3-hydroxypropyl, S-methoxypropy-lor Z-ethoxyethyl group.

The coupling reaction is carried out preferably in a weakly acid to strongly acid medium at temperatures from 5 to 30 C.

The new acid monoazo dyestuffs possess very good neutral afiinity for W001, silk, leather and synthetic poly amide fibers, and dye these fibers from neutral to weakly acid baths in orange to red shades which have very good fastness to light and wet agencies (water, washing, milling and perspiration). The dyeings can be discharged to white: the discharged areas do not darken on exposure to light.

In the examples set forth below the parts and percentages are by weight and the temperatures are in degree centigrade.

EXAMPLE 1 42.4 parts of 2-amino-4-methyl-1.lrdiphenylsulfone- 4-sulfonic acid-di-n-butylamide are diazotized in 150 parts of glacial acetic acid and 30 parts of concentrated hydrochloric acid by dropwise addition of a 50% aqueous solution of 7 parts of sodium nitrite at 20-25 When the nitrite reaction has disappeared, 22.5 parts of 2-aminonaphthalene-5-sulfonic acid are added to the yellow diazo solution and the mass then stirred at 20-30 until the diazo compound is no longer indicated. The deep red solution is stirred into a solution of 40 parts of 30% sodium hydroxide in 1000 parts of a mixture of water and ice. The precipitated red dyestuff is filtered olf, washed with a 2% common salt solution until neutral, and dried. It is a scarlet powder which dissolves in hot water to give red solutions and dyes wool, silk and synthetic polyamide fibers from neutral to weakly acid baths in scarlet shades of very good fastness to light and wet treatments. The dyeings are dischargeable to a good white, which does not darken on exposure to light.

The dyestuff reserves cellulose acetate and cellulose triacetate, polyacrylonitrile and polyester fibers fairly well, and viscose rayon well.

A typical dyeing procedure for this dyestufi" is as follows:

The dyebath is set with 5000 parts of Water, 10 parts of anhydrous sodium sulfate and 1 part of the dyestuff. parts of a wool fabric are entered at 40 and the dyebath heated to 100 in the course of 15 minutes. It is maintained at this temperature for a further 30 minutes, upon which 20 parts of a 10% aqueous solution of acetic acid are added and dyeing continued at the same temperature for 30 minutes. During the dyeing process the evaporated water is continuously replaced. The wool, dyed in a scarlet shade, is removed from the bath, rinsed with water and dried.

EXAMPLE 2 33.1 parts of l-aminobenzene-2-sulfonic acid-(4-cyclohexyl)-phenylester are diazotized in 50 parts of glacial acetic acid and 25 parts of concentrated hydrochloric acid at 540 by dropwise addition of 35 parts of a 20% nitrite solution. On completion of diazotization the clear diazo solution is run into a suspension of 22.5 parts of Z-aminonaphthalene-S-sulfonic acid in 500 parts of water at 15- 20 with stirring. The coupling reaction is brought to a close by dropping in a solution of 30 parts of crystallized sodium acetate in parts of water. The precipitated dyestutf is filtered otf, purified by redissolving and reprecipitation from dilute sodium carbonate solution, and dried.

It is a brick-red powder which is readily soluble in warm water. It dyes wool, silk and synthetic polyamide fibers from neutral to weakly acid baths in orange shades of good light and wet fastness.

.3 EXAMPLE 3 33.3 parts of 1-amino-4-methylbenzene-2-sulfonic acid- (4-tertiary amyl)-phenyl ester are diazotized as described in Example 2 and coupled with 22.5 parts of 2-aminonaphthalene-7-sulfonic acid in the same way. After further processing the dyestuff is obtained as a red powder. It readily dissolves in warm water and dyes Wool, silk and synthetic polyamide fibers from neutral to weakly acid baths in red-orange shades of good fastness to light and wet treatments.

EXAMPLE 4 31.8 parts of 1-amino-5-chlorobenzene-Z-sulfonic acid- (4-chloro)-phenyl ester are diazotized as described in Example 2 and coupled in the same way with an aqueous suspension of 24 parts of Z-methylaminonaphthalene-6- sulfonic acid.

On further processing a red powder is obtained which dissolves with ease in hot water and dyes wool, silk and synthetic polyamide fibers from neutral to weakly acid baths in red shades of good fastness to light and wet treatments.

The following table contains further acid monoazo dyestuffs, which are characterized by the diazo and the coupling component and by the shade of the dyeing on wool.

Table Diazo component Coupling component Shade oithe Example dyeing on No. Wool 5 Z-aminobenzene-l- S-arninonaphthaleneorange.

sull'onie aeid-4- 5-sulf0nic acid. bromophenylester.

6 2-aminc-5-rnethyl- 2-ethylaminonaphredbcnzcne-l-sultonic thalene-S-sulionic orange. acid-4'-isooctylacid. pllcnyl ester.

7 Q'EmiHODEHZOHG-I- 2-amononaphtha1ene- D0.

sulfonic acid phenyl 7-sulr0nic acid. ester.

8 2-aminobenzene-1- do Do.

sulfonic acid (4- ethyl) -pheny1 ester.

9 2-aminobenzene-1- 2-(2-ethoX v)-ethyl- D0.

sulionic acid (-1- aminonaphthalencisopropyD-phenyl fi sulfonic acid. ester.

10 2-nrnino-5-methoxy- 2-(3-hydroxy)pro- Do.

benzene-l-sulfonie pylarninonaphthaacid 4-tert.-buty1- lene-7-sulionic acid. phenyl ester.

Formulae of representative dyestuffs of the foregoing examples are as follows:

EXAMPLE 2 (351111 tort.

Having thus disclosed the invention what I claim is: 1. Acid monoazo dye of the formula l Slog o 0 I 3. The acid monoazo dyestufr of the formula 01 e m-0H3 References Cited in the file of this patent UNITED STATES PATENTS 1,901,515 Hentrich et al Mar. 14, 1933 2,075,076 Zervas et a1 Mar. 30, 1937 2,837,508 Frisch June 3, 1958 2,849,437 Montmollin et al Aug. 26, 1958 

1. ACID MONOAZO DYE OF THE FORMULA 